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|Title:||Quantitative Analysis by Room-Temperature Phosphorescence|
|Author(s):||Warren, Malcolm Wayne, Ii|
|Department / Program:||Chemistry|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||An investigation of room-temperature phosphorescence (RTP) for quantitative analysis of analytes in complex real-sample matrices has resulted in significant improvements in accuracy and precision. A microprocessor-controlled phosphorimeter was developed for the measurements. A combination of real samples and samples spiked with the analytes were determined using RTP. The analytes that were determined include pharmaceuticals in body fluids and pharmaceutical preparations. A combination of standard addition and internal standard techniques along with sophisticated instrumental and mathematical techniques were developed to improve the precision and accuracy of the RTP methods.
The use of an internal standard improves the percent relative standard deviations from 20 percent to 1-3 percent. The method of standard addition is used to improve accuracy from over 100 percent error to under 8 percent error. The intensities of the internal standard and analyte are spectrally stripped from the phosphorescence excitation-emission spectrum of the sample using factor analysis. Because of shifts in the spectral intensity and distribution caused by the sample matrix the spectral intensity and distribution of the analyte and the internal standard are calculated exclusively from the experimental data.
The improved accuracy and precision of RTP as presented in this thesis resulted from an increased understanding of the theoretical and practical aspects of instrumental and sample parameters on the analytical measurement. The effects of the instrument, analyte, and sample matrix on quantitative RTP analysis are demonstrated. Phosphorescence kinetics, light scattering, sample thickness, and non-uniform sample distribution are all explored as factors that influence quantitative analytical results. The practical aspects of data collection and analysis for improved quantitative analysis by RTP are presented. Although these topics have been discussed in the literature with respect to quantitative luminescence measurements, new arguments are introduced along with results from the literature.
The requirements for the instrumental measurement system developed for this study are rather complex because of the data collection and analysis schemes. The instrument described provides automatic data collection and analysis once the sample is placed in the sample module.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.
|Date Available in IDEALS:||2014-12-15|